Audiobook. Peter Gay, an eminent historian who wrote, among many books, The Age of Enlightenment, appears to have written this with a great love for the music of Mozart. And a lively interest in Mozart's strangest weirdness (more about that in a moment), and in debunking the Mozart myths. He says Salieri did not poison him; he likely died of an especially bad episode of rheumatic fever from which he had suffered as a child. He was not chronically depressed in the last year of his life; if he was melancholy, he was also incredibly productive, producing among many pieces, the lovely clarinet concerto and of course the requiem. And his burial was in accordance with the traditions in Vienna at the time, not in a "pauper's grave."
The weirdness that Peter Gay writes about is his scatalogical interest, which seem to be sexual. He wrote to his probable first sexual partner, his cousin, an enthusiastic, excited letter which included this amazing concept, "I shit on your nose." I hardly know what to say.
When Mozart was touring as a young man, his father believed he needed supervision as this was the time when he had developed an interest in his cousin. So when he went for an extended trip to make money for the family in Paris, the father Leopold insisted his mother go with him, even though she was sick. She worsened and died and Mozart delayed giving the news to his father, writing that she was very sick after she was already dead. He later claimed he was breaking the news gradually. Mom's on the roof.